Flash memory is an increasingly popular type of non-volatile memory (NVM). NVM is a type of memory storage that can retain data even while it is not powered on.
A typical flash memory includes a memory array having a large number of memory cells arranged in blocks. Each of the memory cells includes a field effect transistor having a control gate and a floating gate. Pairs of field effect transistors share a common source region. Conventional techniques for forming a common source region involve formation of floating gate and control gate structures prior to etching to form a common source region between the structures. As device sizes decrease a width between field effect transistors and an aspect ratio relating a depth to the common source region to a width between field effect transistors makes it difficult to etch a region for the common source without damaging gate structures of the transistors.